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Journal of Integrative Agriculture 2017年第6期16卷 1211-1226页

作者： Danielle Cooney Hyemi Kim Lauren Quinn Moon-Sub Lee Jia Guo CHEN Shao-lin XU Bing-cheng D.K.Lee Department of Crop Sciences University of Illinois at Urbana-Champaign Urbana 61801 USA Biomass Energy Center for Arid and Semi-arid Lands Northwest A&F University Yangling 712100 P.R. China College of Life Sciences Northwest A&F University Yangling 712100 P.R.China State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Northwest A&F University Yangling 712100 P.R.China

A large portion of the Loess Plateau of China is characterized as “marginal” with serious land degradation and desertification problems. Consequently, two policies, Grain for Green and Western Development Action were established by the Chinese government in response to the demand for ecological protection and economic development in the Loess Plateau. These policies are designed to increase forest cover, expand farmlands, and enhance soil and water conservation, while creating sustainable vegetation restoration. Perennial grasses have gained attention as bioenergy feedstocks due to their high biomass yields, low inputs, and greater ecosystem services compared to annual crops. Moreover, perennial grasses limit nutrient runoff and reduce greenhouse gas emissions and soil losses while sequestering carbon. Additionally, perennial grasses can generate economic returns for local farmers through producing bioenergy feedstock or forage on marginal lands. Here, we suggest a United States model energy crop, switchgrass（Panicum virgatum L.） as a model crop to minimize land degradation and desertification and to generate biomass for energy on the Loess Plateau.

关键词： sustainability bioenergy crop soil erosion Loess Plateau switchgrass

GIS-based detection of land use transformation in the Loess Plateau： A case study in Baota District, Shaanxi Province, China

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Journal of Geographical Sciences 2015年第12期25卷 1467-1478页

作者： GUO Liying DI Liping LI Gang LUO Qiyou GAO Mingjie Institute of Natural Resources and Regional Planning Chinese Academy of Agricultural Sciences (CAAS) Beijing 100081 China Center for Spatial Information Science and Systems (CSISS) George Mason University Fairfax VA 22030 USA

During the past decade, great efforts have been made to boost the land use trans- formation in the Loess Plateau, especially for reducing soil erosion by vegetation restoration measures. The Grain-for-Green project （GFG） is the largest ecological rehabilitation program in China, which has a positive impact on the vegetation restoration and sustainable devel- opment for the ecologically fragile region of west China. Based on the Landsat TM/ETM im- ages for three time periods （2000, 2005 and 2010）, this study applied the GIS technology and a hill-slope analytical model to reveal the spatio-temporal evolutional patterns of returning slope farmland to grassland or woodland in Baota District, Yan＇an city of Shaanxi province. Results showed that：（1） from 2000 to 2010, the area of farmland decreased by approximately 35,030 ha, which is the greatest decrease among all the land-use types, whereas grassland, woodland and construction land increased, of which grassland expanded rapidly by 26,380 ha （2） The annual variation rate of land-use dynamics was 1.98% during the period 2000-2010, of which the rate was 1.05% for the 2000-2005 period and 2.92% for the 2005-2010 period, respectively. Over the past decade, returning farmland to woodland or pastures was the main source of increased grassland and woodland, and the reduction of farmland contributed to the increase in grassland and woodland by 97.39% and 85.28%, respectively. （3） As the terrain slope increases, farmland decreased and woodland and grassland increased significantly. Areas with a slope ranging from 15° to 25° and less than 15° were the focus of the GFG project, accounting for 85% of the total area of farmland reduction. Meanwhile, the reduction in farmland was significant and spatially correlated with the increase in woodland and grass- land. （4） Between 2000 and 2010, the area of destruction of grass and trees in grasslands and woodlands for the reclamation of farmland was approximately 4596 ha. The area subject to the GFG policy was 4456 ha with a slope grea

关键词： Loess Plateau the Grain for Green project land use transformation quantitative detection Baota District

Comparison of transpiration between different aged black locust(Robinia pseudoacacia)trees on the semi-arid Loess Plateau,China

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Journal of Arid Land 2016年第4期8卷 604-617页

作者： JIAOLei LU Nan FU Bojie GAO Guangyao WANG Shuai JIN Tiantian ZHANG Liwei LIU Jianbo ZHANG Di State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Joint Center(or Global Change Studies Beijing 100875China China Institute of Water Resources andHydropower Research Beijing 100038China College of Tourism and Environment Shaanxi Normal UniversityXi'an 710119China College of Earth and Environmental Science Lanzhou UniversityLanzhou 730000China

Black locust （Robinia pseudoacacia） is widely planted throughout the semi-arid Loess Plateau of China. The spatial distribution of this species at different ages is highly heterogeneous due to restoration and management practices. In this study, we aimed to compare the transpiration levels between different aged black locusts at the tree and stand scales, clarifying the physiological status of this species with different ages. Black locust trees with two representative age classes （12 and 28 years） were selected in the Yangjuangou catchment on the semi-arid Loess Plateau. Sap flux density （Fd） and environmental variables （solar radiation, air temperature, relative humidity and soil water content） were simultaneously monitored throughout the growing season of 2014. Tree transpiration （Et） was the product of Fd and sapwood area （As）, and stand transpiration （Ec） was calculated basing on the stand sap flux density （Js） and stand total sapwood area （AsT）. Stomatal conductance （gs） was measured in a controlled environment and hydraulic conductance was estimated using the relationship between transpiration rate and vapor pressure deficit （VPD）. Our results showed that Et and Ec were higher in the 28-year-old stand than in the 12-year-old stand. The gs and hydraulic conductance of 28-year-old trees were also higher than those of 12-year-old trees, and the two parameters were thus the causes of variations in transpiration between different age classes. After rainfall, mean Fd increased by 9% in 28-year-old trees and by 5% in 12-year-old trees. This study thus suggests that stand age should be considered for estimating transpiration at the catchment and region scales in this area. These results provide ecophysiological evidences that the older black locust trees had more active physiological status than the younger ones in this area. These findings also provide basic information for the management of water resources and forests on the semi-arid Loess Plateau.

关键词： sapflow transpiration stand age afforestation restoration Loess Plateau

Temporal and spatial variation characteristics of extreme precipitation on the Loess Plateau of China facing the precipitation process

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Journal of Arid Land 2023年第4期15卷 439-459页

作者： ZHANG Yixin LI Peng XU Guoce MIN Zhiqiang LI Qingshun LI Zhanbin WANG Bin CHEN Yiting State Key Laboratory of Eco-Hydraulic in Northwest Arid Region Xi'an University of TechnologyXi'an 710048China Key Laboratory of National Forestry and Grassland Administration on Ecological Hydrology and Disaster Prevention in Arid Regions Northwest Survey and Planning Institute of National Forestry and Grassland AdministrationXi'an 710048China State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Chinese Academy of Sciences and Ministry of Water ResourcesYangling 712100China

The preceding and succeeding precipitation(PSP)often act together with extreme precipitation(EP),in turn,causing floods,which is an objective component that is often overlooked with regard to summer flood hazards in the arid region of Northwest China.In this study,event-based extreme precipitation(EEP)was defined as continuous precipitation that includes at least one day of EP.We analyzed the spatiotemporal variation characteristics of four EEP types(front EEP,late EEP,balanced EEP,and single day EEP)across the Loess Plateau(LP)based on data acquired from 87 meteorological stations from 1960 to 2019.Precipitation on the LP basically maintained a spatial pattern of"low in the northwest region and high in the southeast region",and EP over the last 10 a increased significantly.The cumulative precipitation percentage of single day EEP was 34%and was dominant for 60 a,while the cumulative precipitation percentage of front,late,and balanced EEP types associated with PSP accounted for 66%,which confirms to the connotation of EEP.The cumulative frequencies of front and late EEP types were 23%and 21%,respectively,while the cumulative frequency of balanced EEP had the lowest value at only 13%.Moreover,global warming could lead to more single day EEP across the LP,and continuous EEP could increase in the northwestern region and decrease in the eastern region in the future.The concept of process-oriented EP could facilitate further exploration of disaster-causing processes associated with different types of EP,and provide a theoretical basis for deriving precipitation disaster chains and construction of disaster cluster characteristics.

关键词： temporal and spatial variation climate change extreme precipitation(EP) event-based extreme precipitation(EEP) Loess Plateau

Optimized nitrogen application for maximizing yield and minimizing nitrogen loss in film mulching spring maize production on the Loess Plateau,China

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Journal of Integrative Agriculture 2024年第5期23卷 1671-1684页

作者： Qilong Song Jie Zhang Fangfang Zhang Yufang Shen Shanchao Yue Shiqing Li State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau College of Natural Resources and EnvironmentNorthwestA&FUniversityYangling712100China Life Science Department Luoyang Normal UniversityLuoyang 471934China

Excessive use of N fertilizers(driven by high-yield goals)and its consequent environmental problems are becoming increasingly acute in agricultural systems.A 2-year field experiment was conducted to investigate the effects of three N application methods(application of solid granular urea once(OF)or twice(TF),application of solid granular urea mixed with controlled-release urea once(MF),and six N rates(0,60,120,180,240,and 300 kg N ha^(-1))on maize yield,economic benefits,N use efficiency,and soil N balance in the maize(Zea mays L.)film mulching system on the Loess Plateau,China.The grain yield and economic return of maize were significantly affected by the N rate and application method.Compared with the OF treatment,the MF treatment not only increased the maize yield(increased by 9.0-16.7%)but also improved the economic return(increased by 10.9-25.8%).The agronomic N use efficiency(NAE),N partial factor productivity(NPFP)and recovery N efficiency(NRE)were significantly improved by 19.3-66.7,9.0-16.7 and 40.2-71.5%,respectively,compared with the OF treatment.The economic optimal N rate(EONR)of the OF,TF,and MF was 145.6,147.2,and 144.9 kg ha^(-1) in 2019,and 206.4,186.4,and 146.0 kg ha^(-1) in 2020,respectively.The apparent soil N loss at EONR of the OF,TF,and MF were 97.1-100.5,78.5-79.3,and 50.5-68.1 kg ha^(-1),respectively.These results support MF as a one-time N application method for delivering high yields and economic benefits,with low N input requirements within film mulching spring maize system on the Loess Plateau.

关键词： maize yield N management economic optimal N rate Loess Plateau

Check dam extraction from remote sensing images using deep learning and geospatial analysis:A case study in the Yanhe River Basin of the Loess Plateau,China

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Journal of Arid Land 2023年第1期15卷 34-51页

作者： SUN Liquan GUO Huili CHEN Ziyu YIN Ziming FENG Hao WU Shufang Kadambot H M SIDDIQUE Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas Ministry of EducationNorthwest A&F UniversityYangling 712100China Institute of Water-Saving Agriculture in Arid Areas of China Northwest A&F UniversityYangling 712100China College of Water Resources and Architectural Engineering Northwest A&F UniversityYangling 712100China College of Natural Resources and Environment Northwest A&F UniversityYangling 712100China The UWA Institute of Agriculture and School of Agriculture&Environment The University of Western AustraliaPerth 6001Australia

Check dams are widely used on the Loess Plateau in China to control soil and water losses,develop agricultural land,and improve watershed ecology.Detailed information on the number and spatial distribution of check dams is critical for quantitatively evaluating hydrological and ecological effects and planning the construction of new dams.Thus,this study developed a check dam detection framework for broad areas from high-resolution remote sensing images using an ensemble approach of deep learning and geospatial analysis.First,we made a sample dataset of check dams using GaoFen-2(GF-2)and Google Earth images.Next,we evaluated five popular deep-learning-based object detectors,including Faster R-CNN,You Only Look Once(version 3)(YOLOv3),Cascade R-CNN,YOLOX,and VarifocalNet(VFNet),to identify the best one for check dam detection.Finally,we analyzed the location characteristics of the check dams and used geographical constraints to optimize the detection results.Precision,recall,average precision at intersection over union(IoU)threshold of 0.50(AP_(50)),IoU threshold of 0.75(AP_(75)),and average value for 10 IoU thresholds ranging from 0.50-0.95 with a 0.05 step(AP_(50-95)),and inference time were used to evaluate model performance.All the five deep learning networks could identify check dams quickly and accurately,with AP_(50-95),AP_(50),and AP_(75)values higher than 60.0%,90.0%,and 70.0%,respectively,except for YOLOv3.The VFNet had the best performance,followed by YOLOX.The proposed framework was tested in the Yanhe River Basin and yielded promising results,with a recall rate of 87.0%for 521 check dams.Furthermore,the geographic analysis deleted about 50%of the false detection boxes,increasing the identification accuracy of check dams from 78.6%to 87.6%.Simultaneously,this framework recognized 568 recently constructed check dams and small check dams not recorded in the known check dam survey datasets.The extraction results will support efficient watershed management and guide future studies on soil erosion in the Loe

关键词： check dam deep learning geospatial analysis remote sensing Faster R-CNN Loess Plateau

持续强降雨影响下黄土高原地形变化分布特征——以延安市顾屯流域为例

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Journal of Geographical Sciences 2024年第3期34卷 571-590页

作者：曹智韩镇李裕瑞王介勇 Institute of Geographic Sciences and Natural Resources Research CASBeijing100101China Key Laboratory of Regional Sustainable Development Modeling CASBeijing100101China Key Laboratory of Degraded and Unused Land Consolidation Engineering Ministry of Natural Resources of ChinaBeijing100101China Qingdao Marine Remote Sensing Information Technology Company Ltd.QingdaoShandong266000China

As China's Loess Plateau has lately witnessed increasingly extreme precipitation events,it is important to analyze the impact of extreme precipitation and identify the conditions for the occurrence of geological disasters.Field surveys can provide detailed geological information in this regard but are time consuming and labor intensive.In this paper,we provide a case study on the Gutun catchment of Yan'an,which was affected by prolonged heavy rainfall in July 2013.We used Digital Elevation Model(DEM)data obtained by processing ZY-03 stereo-pair images before and after the rainy season,including the period of prolonged heavy rainfall mentioned above,to analyze the topographical changes triggered by the rainfall.The results showed the following:(1)The rainy season reduced the elevation of the catchment by about 1.7 cm.The major change in its elevation ranged from-0.5 to 0 m,accounting for 38.41%of the overall area of change and dominating above 70 m of slope height.(2)The rainy season increased the average inclination of the slopes in the area from 28.81°to 28.95°,while the range of their peak inclination was mainly distributed in the range of 24°-36°.(3)Sunny and half-sunny slopes exhibited a greater loss in elevation,while shady and half-shady slopes exhibited an increase in elevation.More drastic topographical changes were observed in the shady and half-shady slopes.(4)The morphology of the area that had undergone a reduction in elevation was characterized by concave slopes,while convex slopes abounded in the area with increased elevation.(5)The sunny or shady properties of the slope aspect constituted the key factor influencing the topographical changes,followed by the height,inclination,and shape of the slopes.The work here can provide guidance for measures related to disaster prevention and mitigation.

关键词： topographical changes extreme precipitation prolonged heavy rainfall disaster prevention and mitigation loess hilly region Loess Plateau

Soil erosion and its causes in high-filling body:A case study of a valley area on the Loess Plateau,China

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Journal of Mountain Science 2023年第1期20卷 182-196页

作者： BAO Han TANG Ming LAN Heng-xing PENG Jian-bing ZHENG Han GUO Guan-miao School of Highway Chang’an UniversityXi’an710064China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing100101China School of Geological Engineering and Geomatics Chang’an UniversityXi’an710054China Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education School of Environmental Science and EngineeringChang’an UniversityXi’an710054China

Large-scale land consolidation projects(LCPs)have been carried out on the Loess Plateau to increase the area of agriculture land.The newly created land is prone to soil erosion under the effects of water and gravity.Taking a typical high-filling body(HFB)formed by LCPs in Yan’an,China as the subject,this study comprehensively investigated the types and causes of soil erosion with multiple methods of field investigation,on-site monitoring and laboratory tests.Results showed that the HFB presented a composite pattern of soil erosion with multiple types mainly including underground erosion,mixed water-gravity erosion,seepage erosion,and scouring erosion.The type of erosion varied spatially in different parts of the HFB depending on the dominant factors,mainly including the groundwater state,rainfall,runoff,gravity action,topography,and soil erodibility.The underground erosion mainly occurred at the positions with higher groundwater level and larger hydraulic gradient,while scouring erosion mainly occurred at the positions with extensive interactions of surface runoff,channel slope gradient and soil properties.And near the leading edge of the top of the slope,a band of mixed watergravity erosion occurred owing to the effects of water and gravity.In addition,nearly saturated soils at the toe of HFB displayed groundwater exfiltration and slope-face slumping.Based on our findings on the causes and variation of soil erosion for the HFB,we proposed the following erosion prevention and control measures to protect the LCPs on the Loess Plateau:to construct drainage ditches and blind ditches to form a complete drainage system,plant alfalfa on the top platform to increase rainfall interception and reduce surface runoff,set seepage ditches and plant deep-rooted plants at the toe of the slope to improve slope toe stability,monitor groundwater level and slope deformation to learn the erosion dynamics and slope stability,and optimize the geometry of HFB such as the slope gradient and slope steps to reduce soil erosion.

关键词： Land consolidation High-filling body Soil erosion Loess Plateau On-site monitoring Influence factors

Assessing sediment connectivity and its spatial response on land use using two flow direction algorithms in the catchment on the Chinese Loess Plateau

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Journal of Mountain Science 2022年第4期19卷 1119-1138页

作者： YAN Xi-qin JIAO Ju-ying TANG Bing-zhe LIANG Yue WANG Zhi-jie State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationChinese Academy of Sciences and Ministry of Water ResourcesYangling 712100China Institute of Soil and Water Conservation Northwest A&F UniversityYangling 712100China University of Chinese Academy of Sciences Beijing 100049China College of Life Sciences Guizhou UniversityGuiyang 550025China

Severe soil and water loss have led to widespread land degradation on the Loess Plateau in China.Exploring the relationship between land use and sediment connectivity can be beneficial to control soil erosion.In this study,three catchments in the Yanhe River Basin on the Loess Plateau were selected to analyse the relationship between land use and sediment connectivity using grey correlation method.Index of connectivity(IC)was employed to quantify sediment connectivity,including two flow direction algorithms(D8 and D-infinity)and two final targets of sediment transport(outlet and main channel of catchment).Then,11 landscape metrics were used to evaluate the land use spatial patterns of catchments.By comparing the IC value ranges,histograms and classes,and their relationship with remote sensing images of the two flow direction algorithms,we find that the D8 algorithm is more suitable for this study area.The results showed that the three catchments are characterized by high sediment connectivity in the grassland and forest close to the channel.In addition,the roads and bare land close to the channel also have high or medium sediment connectivity.Grey correlation analysis showed that landscape division index(DIVISION),fractal dimension index(FRACMN),aggregation index(AI),total class area,patch cohesion index(COHESION),and largest patch index(LPI)indices were the main factors that affect sediment connectivity at the class scale.At the landscape scale,the landscape shape index(LSI),Shannon’s diversity index(SHDI),and gully density have an essential effect on sediment connectivity.This condition provides a way to control the sediment connectivity in the watershed by transforming land use type or changing its spatial pattern,but specific adjustment measures have to be further explored.

关键词： Sediment connectivity Land use Landscape metrics Catchments Loess Plateau

功能区视角下黄土高原碳公平性的时空分异与影响因素

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Journal of Geographical Sciences 2023年第6期33卷 1245-1270页

作者：宋永永夏四友薛东前马蓓蓓刘宪锋 School of Geography and Tourism Shaanxi Normal UniversityXi’an 710119China Key Laboratory of Regional Sustainable Development Modeling Institute of Geographic Sciences and Nat-ural Resources ResearchCASBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China

In this paper, we firstly constructed a theoretical framework based on major function-oriented zones(MFOZs). Then taking the Loess Plateau(LP) as the study area, we revealed the spatio-temporal differences and influencing factors of carbon emission equity by using the carbon equity model, Theil index, and Geo-detector. The results showed that:(1) From 2000 to 2017, the carbon equity of the Loess Plateau showed a downward trend, but the ecological carbon equity remained above 2.3, which was significantly higher than the economic carbon equity.(2) The ecological carbon equity in the Loess Plateau increased from the core of urban agglomeration to the periphery. The spatial pattern of economic carbon equity changed from low in the northeast and high in the southwest to low in the north and high in the south. The ecological support coefficient and economic contribution coefficient of provincial capital cities and their surrounding districts remained low since 2000.(3) The equity of carbon emissions in each function-oriented zone in the Loess Plateau was compatible with its orientation. The ecological carbon equity of the key ecological functional zones(KEFZs) was significantly higher than that of the key development zones(KDZs) and the major agricultural production zones(MAPZs), while the economic carbon equity of the KDZs was significantly higher than that of the MAPZs and the KEFZs.(4) The formation and evolution of the spatial differentiation pattern of carbon equity in the Loess Plateau was the result of the long-term interaction effects of geographic location, social economy, science and technology level, and policy system. Among them, eco-environmental protection policy, government financial support, and geographical location are the key driving factors for the spatial pattern of ecological carbon equity. Geographical location, social economic level, and science and technology level are the key factors driving the spatial pattern of economic carbon equity. According to this study, to achieving carbon equity on t

关键词： major function-oriented zones(MFOZs) equity of carbon emissions spatio-temporal differences influencing factors Geo-detector Loess Plateau